ceo mark zuckerberg says the social network now tops 1 billion active users every month. that amounts to nearly half of the world's nearly 2.5 billion users worldwide. despite facebook's recent troubles, of course, on the stock market, those numbers are incredibly remackable when you consider that less than nine years ago facebook was operating out of a dorm room on harvard's campus. >> doesn't everyone want that success story? you want to catapult something you think of, into this amazing thing from your bedroom. >> there's a wild backstory to it. i'm a total facebook junkie. totally. i am one of the billion. it's changed the world, in a lot of ways. >> is it too much sharing. i remember mi6, security agency in london, that the wife of the agent, the head, the guy heading it up, she posted pictures of him in bathing suit on facebook. running around. got to be careful, privacy settings. >> the thing everybody is worried about, advertising and privacy. that's the deal. going forward. >>> a look at your weather on this holiday weekend. columbus day on monday. stormy and chi